On Sunday, the Financial Times quoted unnamed officials as saying GCHQ was particularly worried that Barclays has given millions of its banking customers free Kaspersky subscriptions. If those customers happen to work for the British military or government, the spooks fear, Kaspersky’s software might help the Russian intelligence services gain access to their information.

However, both Barclays and GCHQ said they have not discussed such concerns. In any case, Barclays said, the bank intends to end its deal with Kaspersky for commercial reasons.

Western intelligence officials have worried for years about Kaspersky’s alleged ties to Russian spies, but that suspicion has gone into overdrive in recent months, largely because Kaspersky’s antivirus software scooped up and sent to Russia the source code for an NSA hacking tool, which was being stored on a Kaspersky-protected PC in the U.S.

That doesn’t necessarily mean Kaspersky then handed over the code to Russian spies—antivirus software is supposed to identify suspicious-looking code and send it home for analysis, and the company said CEO Eugene Kaspersky ordered the code’s deletion after its discovery was reported to him. However, given the clout of the Russian agencies, there is certainly cause for alarm.

The company’s products are banned in U.S. federal agencies and have even been taken off some retailers’ shelves.

However, Western agencies’ concerns over Kaspersky have sometimes extended beyond the defensive. Some of the NSA documents leaked by agency whistleblower Edward Snowden showed that GCHQ was desperate to figure out how Kaspersky’s products worked, because they hampered GCHQ’s own ability to hack into computers protected by those products.